<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		$(function  () {
			var app = function  (sss) {
		    sss = sss || "ddd";
		    //如果有参数，则参数就是自己本省，如果没有参数，则说明参数后面的我那个数值
			if (sss) {
				console.log(sss)
				
			} else{
				console.log(sss)
			}
			
		}
		app()
			
		})
		
	</script>
</html>
